ABSTRACT
Terrestrial plants have been demonstrated to be sources of antimalarial compounds. In Cuba, little is known about antimalarial potentials of plant species used as medicinals. For that reason, we evaluated the antimalarial activity of 14 plant species used in Cuba as antimalarial, antipyretic and/or antiparasitic. Hydroalcoholic extracts were prepared and tested in vitro for the antimalarial activity against Plasmodium falciparum Ghana strain and over human cell line MRC-5 to determine cytotoxicity. Parasite multiplication was determined microscopically by the direct count of Giemsa stained parasites. A colorimetric assay was used to quantify cytotoxicity. Nine extracts showed IC50 values lower than 100 µg/mL against P. falciparum, four extracts were classified as marginally active (SI < 4), one as partially active (Parthenium hysterophorus) exhibiting SI equal to 6.2 and two extracts as active (Bambusa vulgaris and Punica granatum), showing SI > 10. B. vulgaris showed the most potent and specific antiplasmodial action (IC50 = 4.7 µg/mL, SI = 28.9). Phytochemical characterization of active extracts confirmed the presence of triterpenoids in B. vulgaris and polar compounds with phenol free groups and fluorescent metabolites in both extracts as major phytocompounds, by thin layer chromatography. In conclusion, antimalarial use of B. vulgaris and P. hysterophorus was validated. B. vulgaris and P. granatum extracts were selected for follow-up because of their strong antimalarial activity.
Las plantas terrestres han demostrado ser fuentes de compuestos antimaláricos. En Cuba, el conocimiento sobre el potencial antimalárico de las plantas medicinales es escaso. Por esta razón, evaluamos la actividad antimalárica de 14 especies de plantas usadas en Cuba como antimaláricas, antipiréticas y/o antiparasitarias. Se prepararon extractos hidroalcohólicos y se probaron in vitro frente a la cepa Ghana de Plasmodium falciparum para la actividad antimalárica y frente a la línea celular humana MRC-5 para determinar citotoxicidad. La multiplicación de los parásitos se determinó microscópicamente mediante el conteo directo de los parásitos teñidos con Giemsa. Un ensayo colorimétrico se utilizó para cuantificar la citotoxicidad. Nueve extractos mostraron valores de CI50 frente a Plasmodium falciparum por debajo de 100 µg/mL; cuatro extractos se clasificaron como marginalmente activos (IS < 4), uno parcialmente activo (Parthenium hysterophorus) exhibiendo IS de 6.2 y dos activos (Bambusa vulgaris y Punica granatum) mostrando IS>10. B. vulgaris, mostró la acción más potente y específica (CI50 = 4,7 µg/mL, IS = 28,9). La caracterización fitoquímica de los extractos más activos; confirmó la presencia de triterpenoides en B. vulgaris y de compuestos polares con grupos fenólicos libres y metabolitos fluorescentes en ambos extractos como fitocompuestos principales mediante cromatografía en capa delgada. En conclusión, se validó el uso antimalárico de B. vulgaris y P. hysterophorus. Los extractos de B. vulgaris y P. granatum se seleccionaron para seguimiento por su potente actividad antimalárica.
Subject(s)
Humans , Antimalarials/pharmacology , Fibroblasts/drug effects , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Plasmodium falciparum/drug effects , Calorimetry , Cell Line , Cuba , Parasitic Sensitivity Tests , Plant Extracts/classification , Plants, Medicinal/classificationABSTRACT
In this study, a methanolic extract from Echinaster (Othilia) echinophorus was evaluated for activity against Leishmania amazonensis. The extract showed activity against the promastigote and amastigote forms with IC50 values of 62.9 and 37.5 μg.mL-1 respectively. This extract showed a moderate toxicity on macrophages from BALB/c mice. A dose of 100 mg/kg/day was effective when administered during 15 days by intraperitoneal route to BALB/c mice infected experimentally.
Neste estudo descreve-se o efeito de um extrato metanólico de Echinaster echinophorus spp. no parasita Leishmania amazonensis. Em testes com as formas promastigotas e amastigotas, o IC50 do extrato foi 62,9 e 37,5 μg.mL-1, respectivamente. O extrato também tem toxicidade moderada em macrófagos de camundongos BALB/c. O tratamento de camundongos BALB/c infectados com L. amazonensis com doses diárias de 100 mg/kg/dia via intraperitoneal durante 15 dias mostrou-se relativamente efetivo no controle da infecção. Esta investigação confirma a importância de produtos naturais como fonte para a descoberta de fármacos com funções anti-Leishmania.
Subject(s)
Animals , Mice , Antiprotozoal Agents/pharmacology , Echinodermata/chemistry , Leishmania/drug effects , Antiprotozoal Agents/isolation & purification , Leishmaniasis/drug therapy , Mice, Inbred BALB CABSTRACT
A neutral activity of Boophilus microplus in the intestine was identified by electrophoresis in polyacrilamide gel copolymerized with gelatin. The maximum of activity was attained at pH 6.0. The highest specific activity at that pH was obtained with casein substrate. The disappearance of this activity was observed in both substrates after the addition of phenylmethylsulphonyl fluoride in the reaction mixtures. It was very interesting to find out an endopeptidase activity with these characteristics in the intestine, in spite of the fact that the digestive activity in ticks is intracellular at very acid pH, which does not occur in other insects.
Subject(s)
Animals , Endopeptidases , Intestines , Ixodidae , Electrophoresis, Polyacrylamide GelABSTRACT
The cysteine-proteinase activity present in the hemolymph of females crammed with Boophilus microplus at the second oviposition was proved. The enzyme assay was performed using the synthetic N-carbobenzoxi-phenilalanyl-arginil-4-metoxibetan++ +-naphthylamide substrate, and hydrolysis in both raw ovarim extract and hemolymph were observed. The activity was 100 inhibited by trans-epoxisuscinyl-L-leucidamide (4-guadinine) butane, an specific inhibitor for cysteine-proteinase. Polyacrylamide and gelatin-gel electrophoresis showed the existence of only one active band in both samples tested with the same electrophoretic sliding (approximately 38 kDa).